dma: dw: return DMA_SUCCESS immediately from device_tx_status()

There is no point to go throught the rest of the function if first call to
dma_cookie_status() returned DMA_SUCCESS.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/core.c

@@ -1098,12 +1098,12 @@ dwc_tx_status(struct dma_chan *chan,
 	enum dma_status		ret;
 
 	ret = dma_cookie_status(chan, cookie, txstate);
-	if (ret != DMA_SUCCESS) {
+	if (ret == DMA_SUCCESS)
+		return ret;
+
 	dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
 
 	ret = dma_cookie_status(chan, cookie, txstate);
-	}
-
 	if (ret != DMA_SUCCESS)
 		dma_set_residue(txstate, dwc_get_residue(dwc));